Hear me out, here.

The Smash Bros reveals have generally followed a pattern of characters being announced in connection with franchises either being announced or released. So which franchises have yet to be mentioned for Smash? Ice Climbers, F-Zero, ROB, Game & Watch... and Mother/Earthbound. Despite being a franchise that had two representatives in Brawl, no representative has been confirmed for Smash Bros U/3DS.

This isn't the only evidence, though. Earthbound was released on VC last year on the Wii U. This fact in itself isn't particularly notable... what is notable, though, is Nintendo of America's decisions with regard to their website. Earthbound got its own subdomain, earthbound.nintendo.com. As far as I can see, no other VC title has received its own subdomain, with subdomains usually used for new retail releases, like http://fireemblem.nintendo.com/ or http://goldensun.nintendo.com/ - so why did Earthbound get its own subdomain?

When Earthbound was released on VC, Reggie was asked about the possibility of a Mother 3 localisation, and Reggie's response was essentially "we have nothing to announce at this time". In 2009, Reggie said it wasn't in their announcement schedule - this suggests that it wasn't something they were anticipating an announcement for, any time soon. In 2013, it's "nothing to announce at this time".

And one final bit of evidence. Nintendo recently trademarked "EarthBound" in the US... after the release of the VC game, not before it. The trademark wasn't granted until January this year. The timing is curious, in my opinion. For comparison, Game & Wario was trademarked in September 2012, and Donkey Kong Country was re-trademarked in June 2010, a few months before release of DKCR.

So what do you think, does this point to a new Earthbound game being announced at E3? Note that I don't expect it to be Mother 3... I'd expect that to keep its "Mother" name, to be honest.

No

no unless Nintendo decides to flip Itoi the bird and do it without him. Iwata being friends with him and Iwata worked on the Mother series himself I doubt would do that.

I would love it, but I doubt it. The creator said the series is finished,

No way. Itoi is too busy making belly warmers.
http://earthboundcentral.com/2014/06/official-mr-saturn-belly-warmers-coming-soon/

It has about as much of a chance happening as The Last Guardian being released in 2014

Soooo... It's confirmed then?

Would this stop localization of Mother 1 and 3 though, because  it is not continuing the series unless the creator counts official localization of the current games counts as continuing it.

Also, the creator can always change his mind or be persuaded and this can be kept in secret for a surprise.

Id wager that a Mother collection of all 3 games would be more realistic than an enitrely new game. In fact I would ery much like a Mother Collection for 3DS.

The creator could change his mind but it has been ages since Mother 3. The only real reason a person continues a series is because of money, and I dont think he seems the sort to really want some.

No there is absolutely nothing to suggest Nintendo is working on a new Mother game. The creator himself said he'll never make another one.